Researchers in South Australia estimate changes

Answer choices

1. A

   No Impact2% picked this

   The waters around South Australia are the only area in the world where that particular species

   It wouldn't change anything whether these sharks are found elsewhere as well or only around South Australia.

   2%
2. B

   Unclear Impact: most profitable6% picked this

   The sharks that are the most profitable to catch are those that tend to remain in the same area of ocean year after year

   We have no idea if this particular species of shark the argument is discussing is among those sharks that are "the most profitable" to catch, so we won't know whether this answer has any bearing on this argument.

   6%
3. C

   No Distinction / No Impact19% picked this

   A significant threat to shark populations, in addition to commercial shark fishing, is "incidental mortality" that results from catching sharks in

   This is a "timeless" idea. It's saying there is always some level of threat to shark populations that they'll get caught in a net intended to catch something else. But without knowing whether that threat has increased, decreased, or stayed the same since 1973, this answer has no impact on the conversation.

   19%
4. D

   No Impact24% picked this

   Most of the quotas designed to protect shark populations limit the tonnage of sharks that can be taken and not

   The existence of quotas, i.e. "You may only catch up to 20 sharks per day" has nothing to do with CPUE. CPUE is the idea that boats are currently able to catch 4 sharks per hour. So if there's a quota of 20 sharks, then they'd only be able to do 5 hours of catching in a day before they had hit their quota. But we don't care at all about how many hours they're allowed to be out there catching sharks. We just care about how efficiently they're catching sharks when they're out there (i.e. how many sharks per hour). This is saying quotas are usually based on the weight of the sharks, rather than the number of sharks, but again, we don't care about quotas because we don't care about how long they're fishing before they've hit their quota. We care about how many sharks they can catch in an hour.

   24%
5. E

   Correct48% picked this

   Since 1980 commercial shark-fishing boats have used sophisticated electronic equipment that enables them to locate

   Why this is right

   This allows us to argue that the population of this shark species is not at its 1973 level. We can argue that there are actually not as many sharks in the water as before. After all, our methods of finding sharks have improved since 1973, so we should be able to catch more sharks per hour than we could back then. So if our CPUE is still only 4 sharks per hour, despite our better shark-finding techniques, it suggests that there are fewer sharks to be found.

   Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

   48%